# SecTransformCreateFromExternalRepresentation(_:_:) Creates a transform instance from a dictionary of parameters. ``` func SecTransformCreateFromExternalRepresentation(_ dictionary: CFDictionary, _ error: UnsafeMutablePointer?>?) -> SecTransform? ``` ## Parameters `dictionary` The dictionary of parameters. `error` An optional pointer to a CFErrorRef. This value is set if an error occurred. If not NULL the caller is responsible for releasing the CFErrorRef. ## Return Value A pointer to a SecTransformRef object. You must release the object with CFRelease when you are done with it. A NULL will be returned if an error occurred during initialization, and if the error parameter is non-null, it contains the specific error data. ## Discussion --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)